Egonomics_and_work_place_engineering

Ergonomics & Work Place Engineering
A ventilation intervention Study for Industry
Submitted to:
Ms. Renjini G
Dept. of Fashion Technology
NIFT, Bengaluru
Submitted by:
Aishwarya Iyer B MFT/17/25,
Tejas.M.P MFT/17/65
National institute of Fashion Technology, Bengaluru
Tejas.mp@nift.ac.in, aishwarya.iyer7411@gmail.com

CONTENTS
CHAPTER 1 INTRODUCTION
1.1 INDUSTRIAL VENTILATION
1.2 PURPOSE OF A VENTILATION SYSTEM
1.3 PARTS OF AN INDUSTRIAL VENTILATION SYSTEM
1.4 THE IMPORTANCE OF INDUSTRIAL VENTILATION
1.5 TWO MAIN METHODS OF INDUSTRIAL VENTILATION
1.6 EFFECTS OF POOR VENTILATION
CHAPTER 2 LITERATURE REVIEW
2.1 MEASUREMENT OF THERMAL CONDITIONS
2.2 AIR FLOW MEASUREMENT
2.3 AIR MOVEMENT
2.4 VENTILATION SYSTEMS
2.5 HOW THE BODY HANDLES HEAT
2.6 CONTROL OF HEAT IN THE WORKPLACE
CHAPTER 3 STANDARDS FOR VENTILATION
3.1 ASHRAE STANDARD 62
3.2 VENTILATION OF BUILDINGS
3.3 TESTING
3.4 NATURAL FILTRATION
CONCLUSION
REFERENCES

1
CHAPTER 1
INTRODUCTION
Employee morale can be impacted in both positive and negative ways by the workplace
environment. Workplace environment plays a major role in the performance and productivity
of an employee. Most industries have an unsafe workplace environment and are most time
unhealthy too. This study is focused on the workplace environment in a health facility and
how it affects the health worker. Lack of ventilation, excessive noise, inappropriate lighting,
poor supervisor support, poor work space, poor communication, poor fire safety measures for
emergencies, and lack of personal protective equipment, can adversely affect the productivity
of the employee. Health worker’s productivity and performance can decrease due to poorly
planned workplace environment as this adversely affects their morale and may give rise to
poor motivation and no job satisfaction as a result.1
The production space (cutting, sewing
and finishing sections) of garment sector is usually human labour intensive. The workers’
health, comfort and performance can be influenced by the quality of the production space
Hence, optimal working environment is necessary to maximise productivity Poor indoor
environment has harmful impacts on workers’ health resulting in a high incidence of illness.
The most frequent incidences are headache (98%), respiratory problem (36%), vomiting
(28%), fatigue (28%) and fainting (18%) (Mridula et al., 2009). These are likely to result
from the humid indoor conditions and lack of ventilation of the factories. However,
improving the indoor workspace environments for workers’ safety and comfort is also
important. There is a significant amount of heat gain inside the building from the artificial
luminaires, workers’ body temperature and constantly in-use equipment (e.g. sewing
machines, iron machines, etc.). The resultant gained heat is usually trapped at indoor due to
lack of air changes. The factory owners use mechanical means to keep the indoor
environment comfortable consuming a significant portion of energy. Local regulatory
frameworks generally guide about window-floor areas for buildings which may not apply to
the deep-planned one and need contextualisation.2

2
Categories of ventilation.
1. Mechanical ventilation refers to any system that uses mechanical means, such as a
fan, to introduce subaerial air to a space. This includes positive pressure ventilation,
exhaust ventilation, and balanced systems that use both supply and exhaust
ventilation.
2. Natural ventilation refers to intentionally designed passive methods of introducing
subaerial to a space without the use of mechanical systems.
3. Mixed mode ventilation /hybrid ventilation systems use both natural and
mechanical processes.
4. Infiltration is the uncontrolled flow of air from outdoors to indoors through leaks
(unplanned openings) in a building envelope. When a building design relies on
environmentally driven circumstantial infiltration to maintain indoor air quality, this
flow has been referred to as adventitious ventilation.3
1.1Industrial Ventilation
Ventilation system in a building brings in "fresh" outdoor air and removes the "contaminated"
indoor air.
In a workplace, ventilation is used to control exposure to airborne contaminants. It is
commonly used to remove contaminants such as fumes, dusts, and vapours, in order to
provide a healthy and safe working environment. Ventilation can be accomplished by natural
means (e.g., opening a window) or mechanical means (e.g., fans or blowers).
Industrial systems are designed to move out (exhaust) and bring in (intake) a specific amount
of air at a specific speed (velocity), which results in the removal of undesirable contaminants.
While all ventilation systems follow the same basic principles, each system is designed
specifically to match to the type of work and the rate of contaminant release at that
workplace.4

3
1.2 PURPOSE OF A VENTILATION SYSTEM
There are four purposes of ventilation:
1. Provide a continuous supply of fresh outside air.
2. Maintain temperature and humidity at comfortable levels.
3. Reduce potential fire or explosion hazards.
4. Remove or dilute airborne contaminants.
1.3 PARTS OF AN INDUSTRIAL VENTILATION SYSTEM
An industrial ventilation system has two main parts: a fresh air supply system and an exhaust
system.
In general, the supply system is a heating, ventilation, and air-conditioning system (HVAC)
and consists of:
 Air Inlet,
 Air Filtering Equipment,
 Heating/Cooling Equipment,
 Fan,
 Ducts,
 Air Distribution Registers.
The exhaust system consists of:
 An "air intake" area,
 Ducts to move air from one area to another,
 Air cleaning device(s),
 Fan(s) to bring in outside air and exhaust the indoor contaminated air, and
 Discharge stacks.4
1.4 THE IMPORTANCE OF INDUSTRIAL VENTILATION
Industrial facilities are often used in places that produce toxic airborne particles,
hazardous chemical fumes, dust, and other harmful vapours. To mitigate the effect of
these floating dangers, proper industrial ventilation needs to be installed. Put simply,

4
industrial ventilation gets rid of the bad air and replaces it with fresh air from outside.
Ventilation is a necessary part of any industrial facility that will produce harmful air
pollutants in a confined space where employees work. It not only cleans the air
employees will breathe, it also allows for better temperature control and reduces the risk
of fire in the facility.
1.5 TWO MAIN METHODS OF INDUSTRIAL VENTILATION
Diluted Ventilation:
The industrial ventilation system required for diluted ventilation does just what the name
suggests. It dilutes the polluted air by bringing in pure air and getting rid of only some of the
unclean air. The advantages of this type of system include lower costs and less maintenance.
However, these systems obviously do not completely take care of the polluted air in your
workplace and thus should not be used in areas with very large amounts of gas or smoke, or
in areas with especially toxic forms of fumes. On the other hand, this type of system will due
for minor quantities of mildly noxious fumes.
Local Exhaust Ventilation:
The industrial ventilation systems used for this type of ventilation seize the polluted
discharges at the source and discard them outdoors. This ventilation is sufficient for any type
of contaminations and is thus obligatory for extremely noxious substances in the air. The
down side to these systems is greater installation and maintenance cost and time. However,
this type actually uses less energy, which lowers long-term costs.
Industrial ventilation is a necessity for the health of your employees and the success of your business.
Imperial Systems offers high quality ventilation equipment and is interested in partnering with you for
your ventilation needs.5
Comparison of Ventilation Systems6
Dilution Ventilation Local Exhaust Ventilation
Advantages Disadvantages Advantages Disadvantages
Usually lower
equipment and
installation costs.
Does not completely
remove contaminants.
Captures contaminant
at source and removes
it from the workplace.
Higher cost for
design, installation
and equipment.

5
Requires less
maintenance.
Cannot be used for
highly toxic
chemicals.
The only choice for
highly toxic airborne
chemicals.
Requires regular
cleaning, inspection
and maintenance.
Effective control
for small amounts
of low toxicity
chemicals.
Ineffective for dusts
or metal fumes or
large amounts of
gases or vapours.
Can handle many
types of contaminants
including dusts and
metal fumes.
Effective control
for flammable or
combustible gases
or vapours.
Requires large
amounts of heated or
cooled makeup air.
Requires smaller
amount of makeup air
since smaller amounts
of air are being
exhausted.
Best ventilation for
mobile or dispersed
contaminant
sources.
Ineffective for
handling surges of
gases or vapours or
irregular emissions.
Less energy costs
since there is less
makeup air to heat or
cool.
1.6 EFFECTS OF POOR VENTILATION
Poor ventilation can not only lead to the build up of mould and condensation, but it is also
a health hazard. It is therefore important that you ensure that the industry is properly
ventilated in order to ensure inhabitants' well-being.
Condensation
Condensation is especially prevalent during the colder winter months, as the difference in
temperature between the cold outdoors and warm indoors is at its most dramatic. Moisture
will build up in the air as you breathe and condense on windows and walls.
Mould growth
Poor ventilation and high humidity industry can eventually lead to the build-up of mould on y
floors, walls, ceiling and even furniture. Mould is easily identified by black or green spotting
and a musty smell and can cause health problems, such as allergic reactions and cold-like
symptoms.

6
Damaged walls
High levels of moisture in the air can wrinkle and peel wall paint, leading to possible health
issues and extra maintenance costs.
Low oxygen levels
Poor ventilation will result in an eventual build-up of carbon dioxide and little oxygen, which
means you could suffer from shortness of breath, headaches and fatigue.7

7
CHAPTER 2
LITERATURE REVIEW
Buildings, as they are designed and used today, contribute to serious environmental problems
because of excessive consumption of energy and other natural resources. The close
connection between energy use in buildings and environmental damage arises because
energy-intensive solutions sought to construct a building and meet its demands for heating,
cooling, ventilation, and lighting cause severe depletion of invaluable environmental
resources. However, buildings can be designed to meet the occupant’s need for thermal and
visual comfort at reduced levels of energy and resources consumption. Energy resource
efficiency in new constructions can be affected by adopting an integrated approach to
building design. Thus, in brief, an energy-efficient building balances all aspects of energy use
in a building – lighting, space-conditioning, and ventilation – by providing an optimized mix
of passive solar design strategies, energy efficient equipment, and renewable sources of
energy
Indoor air quality the most common concept for an indoor air quality is used is an equivalent
to the cleanliness of indoor air. There is a variety of different air pollutants with different
potential effects on comfort and health that should be taken into account while designing
building services systems. Some examples of sources of indoor air pollution:
• Inside of the building:
1. People
2. Building materials
3. Technical equipment
4. Furniture o Microbial growth
5. Pets
6. Tobacco smoke
• Outside of the building:
1. Traffic
2. Industries
3. Plants (pollen)8

8
During the past few decades the health considerations have become increasingly important in
conjunction with comfort. Due to the growing price of energy, people have renovated many
buildings, unfortunately without paying enough attention to the indoor climate. There are
many factors in indoor climate that may cause health problems , e.g. noise, thermal climate,
light, but poor indoor air quality is often the most critical one.9
2.1 Measurement of Thermal Conditions
The air temperature is conveniently measured by means of the ordinary mercury-in-glass
thermometer. For the determination of atmospheric humidity the sling hygrometer, consisting
of wetand dry-bulb thermometers, is a suitable instrument. The wet-bulb temperature is of
importance in warm atmospheres, and from the observed dry- and wetbulb temperatures the
humidity of the air, relative or absolute, is readily ascertained by reference to psychrometric
tables.
The eupatheoscope
Fig. 1
The eupatheoscope has variable heat input, while its surface temperature is kept almost
constant. Winslow et al., 1935 first described an instrument with the reversed principle of
constant heat input and variable surface temperature. The Thermo-Integrator is, like the
eupatheoscope, a hollow copper cylinder, electrically heated with constant heat input. The
surface temperature of the instrument is recorded by means of thermocouples distributed over
its periphery and connected to an automatic recorder. Other normated temperatures using the
same idea but with different names are Equivalent Homogeneous Temperature (EHT) (Wyon

9
et al., 1989, Bohm et al., 1990). An alternative method for the determination of "equal
thermal environments" is the RST or Resultant Surface Temperature and the associated
"equivalent temperature" (Mayer et 19 al., 1993). A constant surface heat loss is assumed and
the temperature of the surface segment (RST-value) that solves the heat balance equation, for
inhomogeneous conditions is used as a measure of the climatic influence from the
environment.
Improvisation of general ventilation in Industry
• If you have ventilation systems or free standing fans in the factory, make sure that
they increase the natural flow of air through the factory and not try to blow air against
any prevailing wind (Fig 2)
• Ensure that hot, stale air that rises to the factory roof can easily be removed and
replaced with fresh air (Fig 3)
• Make sure that all fans are well maintained and regularly cleaned so that they work
efficiently.
• Ensure that the air-flow to and from fans is not blocked (Fig 4)
• Try to ensure that any “hot” processes such as the ironing section are sited next to the
“down wind” wall so that the heat is extracted directly outside rather than being
spread around the factory (Fig 5).
Fig 1 Fig 3
Fig 4
Fig 5

10
ASHRAE Standard 62.1
Ventilation air, as defined in American Society of Heating, Refrigerating and Air-
conditioning Engineers (ASHRAE) Standard 62.1, is that air used for providing acceptable
indoor air quality. When people or animals are present in buildings, ventilation air is
necessary to dilute odours and limit the concentration of carbon dioxide and airborne
pollutants such as dust, smoke, and volatile organic compounds (VOCs). Ventilation air is
often delivered to spaces by mechanical systems which may also heat, cool, humidify and
dehumidify the space. Air movement into buildings can occur due to uncontrolled infiltration
of outside air through the building fabric or the use of deliberate natural ventilation strategies.
Advanced air filtration and treatment processes such as scrubbing, can provide ventilation air
by cleaning and / or recirculating a proportion of the air inside a building. Ventilation is one
of the most important engineering controls available to the building manager for improving
or maintaining the quality of the air in the occupational work environment. Broadly defined,
ventilation is a method of controlling the environment with air flow. The sense of thermal
comfort (or discomfort) results from an interaction between air temperature, relative
humidity, and air movement. Air flow is also important for ensuring air moves from clean to
dirty and out. In general, the air flow patterns should move from 'clean' spaces into 'more
dirty' areas. A good rule of thumb is to keep air flowing from clean to dirty, so that children
are not breathing polluted air. This is particularly important for places such as janitorial
closets where cleaning supplies are often stored, unused locker rooms with dry traps and
leaking sewer gases, and boiler rooms with back drafting heating appliances.10
2.2 Air Flow Measurement
Air flow can be used to calculate ventilation is the mixing of outside air with inside air. The
purpose of the mixing is to keep pollutants and carbon dioxide at the appropriate levels. The
American Society of Heating, Refrigerating, and Air Conditioning Engineers, Inc (ASHRAE)
issues guidelines to ensure the levels of carbon dioxide and other indoor air pollutants are
kept at appropriate levels. These guidelines can be reviewed in the Carbon Dioxide section.
When designing air flows you want to move polluted air to the outside. You also want to
keep air from places like the science classroom, kitchen, and restrooms from flowing into
office space or classroom space. This can also be called “source control”. In addition to being
an important part of ventilation, air movement contributes to the perception of comfort.
Room occupants will be more comfortable with some air movement.11

11
2.3 Air Movement
Increased ventilation commonly means more air movement, though the statement does not
apply without exception. In warm weather we throw open our windows to get more air
movement. But substantial increases in the ventilation rate are necessary to gain appreciable
increments in the air movement. This is shown by observations, as yet unpublished, made by
the writer and his colleagues. Thus, in a closed room with less than one air change per hour
the velocity was 10 or 11 feet per minute, while to raise the velocity to 20 feet per minute by
natural ventilation it was necessary to raise the ventilation rate to twenty air changes per hour.
In factories the movement of persons and machinery tends to cause increased air movement,
and in a factory building the air will probably not be very stagnant if the fresh air supply
reaches the recommended figure. But in summer much more ventilation than that necessary
to remove odours is very desirable. Copious ventilation is desirable in summer, on physical
grounds as well as for the removal of odours.
2.4 Ventilation systems
Itshallbe designed to have the capacity to supply the minimum outdoor airflow rate determined
in accordance with below on the occupancy of the space and the occupant load or other
parameter as stated therein. The occupant load utilized for design of the ventilation system shall
be based on expected average occupant load provided the average occupant load is not less than
one-half the numberdeterminedfromtheestimatedmaximumoccupantload rate indicated in
below Table
OCCUPANCY CLASSIFICATION
ESTIMATED MAX
OCCUPANT LOAD, PERSONS
PER 1,000 SQUARE FEET
OUTDOOR AIR [Cubic feet
per minute (cfm) per person]
UNLESS NOTED
Education
Auditoriums
Classrooms
Corridors
Laboratories
Libraries
Locker rooms
Music rooms
Smoking lounges
Training shops
150
50
—
30
20
—
50
70
30
15
15
0.10 cfm/ft2
20
15
0.50 cfm/ft2
15
60
20
Theaters
Auditoriums
Lobbies
Stages, studios
Ticket booths
150
150
70
60
15
20
15
20

12
Workrooms
Bank vaults
Darkrooms
Duplicating, printing
Meat processing
Pharmacy
Photo studios
5
—
—
10
20
10
15
0.50 cfm/ft2
0.50 cfm/ft2
15
15
15
Education
Auditoriums
Classrooms
Corridors
Laboratories
Libraries
Locker rooms
Music rooms
Smoking lounges
Training shops
150
50
—
30
20
—
50
70
30
15
15
0.10 cfm/ft2
20
15
0.50 cfm/ft2
15
60
20
2.5 HOW THE BODY HANDLES HEAT
In hot, humid conditions, workers can lose heat and cool down naturally in a number of
ways:
• By evaporation – by sweating
• By radiation – by increasing blood flow and the temperature of the skin surface. It needs
cooler objects nearby for this method to be effective
• By convection – exchange of heat between the body surface and the surrounding air. It
needs air movement to be effective
• By conduction – direct exchange of heat between the body and cooler, solid objects.
2.6 CONTROL OF HEAT IN THE WORKPLACE
There are a number of basic approaches to tackling heat hazards in garment factories. All
involve reducing exposure by keeping heat away from workers through: - engineering
controls; - changing work practices; - use of personal protective equipment

13
CHAPTER 3
STANDARDS FOR VENTILATION
There are no EPA standards for air movement, but there are Occupational Safety and Health
Administration (OSHA) and American Society of Heating, Refrigerating and Air-
conditioning Engineers (ASHRAE) guidelines. Ventilation is addressed in specific OSHA
standards for the general industry, shipyard employment, long-shoring, and the construction
industry. There are two basic categories of ventilation in the OSHA standards: general
exhaust ventilation (dilution ventilation) and local exhaust ventilating. OSHA is focused on
providing guidelines for industry, but these basic categories also apply in residential or school
building settings. For example, local exhaust ventilating might be used in the bathroom or
kitchen.
3.1 ASHRAE Standard 62
ASHRAE Standards specify that outside air for ventilation purposes should be introduced at
the lowest volume necessary to maintain adequate indoor air quality. ASHRAE Standard 62-
l989, Ventilation for Acceptable Indoor Air Quality, specifies the outdoor air ventilation
requirements at a minimum of 15 cfm per person in non-smoking areas, regardless of
occupant usage, and a minimum of 60 cfm per person for smoking areas. Also the
concentration of CO2 should not exceed 1,000 parts per million in conditioned spaces.
ASHRAE Standard 62-2001 offers two methods for determining the amount of outdoor air
required to properly ventilate indoor occupied spaces for acceptable IAQ: the Ventilation
Rate Procedure and the IAQ Procedure.

14
The standard is used to calculate the minimum outdoor airflow required at the system
level 12
Y = X / (1+ X - Z)
Vot = Y x Vst
Where:
X = Von/Vst = uncorrected outdoor airflow fraction
Y = Vot/Vst = corrected outdoor airflow fraction
Z = largest F = critical-space ventilation fraction
F = Vo
/Vs = space ventilation fraction
Von = ∑Vo = sum of space ventilation airflows
Vot = Y x Vst = required system outdoor airflow
Vo = space ventilation airflow
Vs = space primary airflow
Vst = ∑Vs = total supply airflow
Indoor air quality shall be considered acceptable if the required rates of acceptable outdoor
air in below Table are provided for the occupied space.

15
3.2 Ventilation of Buildings-
In the case of an industrial building having a significant internal heat load due to
manufacturing processes, the following items may be considered when designing for the
maximum possible control of thermal environment 13
1. Orientation of the building with respect to the direction of the prevailing winds and of
the path of the sun in the sky and to the location of adjoining buildings.
2. Configuration of the building and the manufacturing processes In It.
3. Proper inlets (windows and other openings) and their location with respect to outlet
openings.
4. Mechanical ventilation including selection and disposition of fans,inlet grilles and
arrangement of ducts.
In the case of industrial buildings wider than 30m, the ventilation may be augmented by roof
ventilation.
The volume of air required shall be calculated by using both the sensible heat or latent heat as
the basis. The larger of the two figures obtained should be used in actual practice
Volume of air required for removing sensible heat when the amount of sensible heat given
off by different sources namely the sun, the manufacturing processes machinery, occupants
and other sources is known and a suitable value for the allowable temperature rise is
assumed, the volume of outside air to be provided for removing the sensible heat may be
calculated from:
where,
Q1= quantity of air in m³/h,
Ks = sensible heat gained in kcal/h, and
t = allowable temperature rise in°C.
Volume of air required for removing latent heat If the latent heat gained from the
manufacturing processes and occupants is also known and a suitable value for the
allowable rise in vapour pressure is assumed. 13

16
where
Q2 = quantity of air in m³/h,
k1 = latent heat gained in k cal/h, and
H= allowable vapour pressure difference in mm of mercury.
3.3 TESTING
All parties concerned shall agree to the objects of test, methods and duration of test,
degree of accuracy required and state of ventilating equipment under test. The plant should
be run during normal working hours and adjusted properly prior to the test.
Amount of Air
Positive Ventilation : The volume of outside air by positive ventilation shall be measured
by appropriate instruments, such as a properly calibrated anemometer, velocity meter and
pitot tube. To measure the average velocity of air flow, it is necessary to make a traverse
of the instrument over the cross-sectional area of the intake openings or ducts und obtain
the average velocity from these results. The volume of air is given by14
Q=AV
Where
Q= volume of air in m³/m in,
A = free area of intake openings of ducts in m³, and
V = average velocity of air in m/min.
Exhaust of Air -The volume of exhaust air shall be measured in the same manner as in the
case of positive ventilation by measurement of air velocity and area of exhaust ducts or

17
openings, and multiplying the one with the other.
3.4 Natural filtration
This is difficult to measure as it varies from time to time. The amount of outside air by
natural infiltration through doors or windows or through other openings depends on direction
and velocity of wind outside and/or convection effects arising from temperature of vapour
pressure difference (or both) between inside and outside of the work room. 15
Ventilation due to wind outside is given by the formula:
Q=EAV
where
Q= volume of air in m³/min;
A = free area of inlet openings in m²;
v = velocity of wind in m/min; and
E = co efficient which varies from 0.5 to 0.6 when .openings face wind, and 0.2S to 0.35
when openings are at an angle.
Ventilation due to convection effects arising from tempera-ture difference between inside and
outside is given by:
Q.= 7.0 √ (tr - to)
where
Q.= volume of air in m/min;
A = free area of inlet openings in m²;
h = vertical distance between inlets and outlets in mm;
tr =average temperature of indoor air at the outlet, in °C; and
to = temperature of outdoor air in °C.

18
CONCLUSION
Employers shall create a thermal environment that meets acceptable standards. The thermal
environment shall be in conformity with workers health and shall not disturb their work. In a
building or a workshop with normal condition, each worker shall have a space of at least 10
cubic meters. The workplace shall be protected from the ultra-heat of the sun. The production
method which does not generate heat should be adopted. If the production generates extreme
heat, the employer shall reduce the heat by: - having the heat generating parts insulated; -
having the heat absorbed and diverted from the original source. In case the heat at the
workplace is high affecting the workers’ health or disturbing their work, the employer shall
seek every possible means to cool the workplace such as by having fans, air coolers and air
conditioners installed.

19
REFERENCES
1. https://www.omicsonline.org/peer-reviewed/impact-of-workplace-environment-on-
health-workers-92181.html
2. http://www.plea2014.in/wp-content/uploads/2014/12/Paper_1A_2176_PR.pdf
3. https://www.osha.gov/dts/osta/otm/otm_iii/otm_iii_3.htmlW
4. https://www.journals.elsevier.com/international-journal-of-industrial-ergonomics
5. https://www.isystemsweb.com/industrial-ventilations-systems-workplace/
6. Local Exhaust Ventilation and Application: A Review Nor Halim Hasan, M. R Said
and A.M Leman IJET-IJENS Vol:12 No:04
7. http://www.coolbricks.eu/fileadmin/Redaktion/Dokumente/Publications/24-
7_ventilation_system.pdf
8. Ventilation for Acceptable Indoor Air Quality ANSI/ASHRAE Standard 62-2001
9. http://www.inive.org/medias/ECA/ECA_Report11.pdf
10.lnternational Standard IS0 7730 (1 984) Moderate thermal environments -
Determination of the PMV and PPD indices and specification of the conditions for
thermal comfort. Geneva.
11.https://www.trane.com/commercial/Uploads/PDF/520/ISS-APG001-EN.pdf
12.https://archive.org/details/gov.in.is.3103.1975
13.https://www2.iccsafe.org/states/oregon/07_mechanical/07_PDFs/Chapter%204_Venti
lation.pdf
14.https://www7.nau.edu/itep/main/eeop/docs/airqlty/AkIAQ_AirMovementAirFlow.pdf
15.B Purshotama, Humidification & Ventilation management in textile industry,
pubished by Woodhead Publishing India in Textiles 2009.

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